Letter from Lhasa, number 226. (Ruest 2009): Virtualization. A Beginner’s Guide
by Roberto Abraham Scaruffi
Ruest, D., and N. Ruest, Virtualization. A Beginner’s Guide, McGraw-Hill, 2009.
(Ruest 2009).
Danielle Ruest,
Nelson Ruest
What is virtualization?
“As you now know, virtualization is a technology that partitions a computer into several independent machines that can support different operating systems and applications running concurrently. The great advantage of this is that you can take a physical server that is running at 10 percent utilization and transform it into one running at 60 to 80 percent utilization by loading it up with multiple virtual machines. The underlying hypervisor software will run directly on the hardware and act as a coordinator to manage multiple operating systems in VMs. In this situation, each instance of an operating system running in a virtual machine becomes a self-contained operating environment that runs on top of the hypervisor and behaves as if it is a separate computer.” (Ruest 2009, p. 30).
“Virtualization removes the physical hardware dependencies from server operating systems, allowing them to be moved and recovered like never before. Instead of having to perform scheduled hardware maintenance at some obscure hour over the weekend, server administrators can now live migrate a VM to another physical resource and perform physical server hardware maintenance in the middle of the business day.” (Ruest 2009, p. xvi).
Virtualization permits not to underuse resources. Consequently there are even considerable cost reductions.
“Datacenters around the world are looking to virtualization technologies to reduce their carbon footprint. They are tired of running server systems at 10 percent or less utilization ratios, yet having these systems continue to draw power and require space and cooling just like any other machine. Virtualization promises server hardware usage ratios of 80 percent or more while delivering the same workloads on a much smaller hardware, and therefore carbon, footprint” (Ruest 2009, p. 4).
“Virtualization will have several impacts on your existing datacenter, including:
“▼ The impact on your network
“■ The impact on your operations
“■ The impact on your business processes
“▲ The impact on your bottom line”
(Ruest 2009, p. 21).
The book drives through all the software and hardware technicalities for virtualizing an IT department and a company. It is an investment which will immediately translate in generalized saving and in increased speediness and security.
Ruest, D., and N. Ruest, Virtualization. A Beginner’s Guide, McGraw-Hill, 2009.
